Major attributes of pig lean meat quality are colour and the amount of exudate lost during storage. These can be influenced by genotype and preslaughter handling. Surprisingly, there is hardly any Information on the inherent meat quality potential of different breeds of pig in the UK and this is particularly true of the traditional breeds. While these may form a negligible part of the British pig population, with the increasing concern at the apparent recent increase in the incidence of PSE meat, use of genes from possibly-resistant traditional breeds in commercial hybrids might be valuable to improve quality. In this work therefore, eleven breeds of pig were compared, each represented by about twenty animals from at least two different source herds (see Table 1). Both gilts and castrates were represented. They were fed a diet containing 20% protein ad libitum and slaughtered at a live weight averaging 62 kg after having been subjected to the minimum of stress. The pH in the H. longissimus dorsi (LD) was measured at 45 min post mortem. After overnight chilling the carcasses were cut into primal joints and the loin joint scored for shape of the LD, coarseness of the grain of the muscle fibres and ‘setting’ of the joint. Setting is an important quality characteristic in that it facilitates butchery and enhances the appearance of retail cuts. Measurements of reflectance and loss of exudate during storage were made on the LD. Reflectance was measured using an EEL meter and exudation was determined after storage at 1°C for 3 days.

The meat industry has come under increasing pressure in recent years: there is increased competition between the meat species and between neat and non-meat alternatives. Earlier qualitative consumer research (Wright and Slattery, 1986) highlighted several factors causing concern which were apparently affecting meat consumption. These factors included an awareness of the causal link between dietary fat and coronary heart disease; interest in the quality of meat; concern regarding the use of growth hormones and/or food additives and concern regarding animal welfare issues. A greater understanding of consumer attitudes towards meat which might be effecting a reduction in consumption is needed if the industry is to devise successful production and marketing strategies. This forms the rationale for this investigation.

Healthy eating is now a feature of the strategies of many organisations in the food industry. This has developed since the recommendations of the NACNE (National Advisory Committee on Nutrition Education) report, and COMA (Committee on Medical Aspects of Food Policy) report on cardiovascular disease were published. These led to considerable media coverage and stimulated consumer demand for healthy choices in their shopping. This research is concerned with the consumer reaction to dietary recommendations, using milk as a case study. The increased interest in diet and health can be demonstrated by the increased market share of some food products: wholemeal bread now accounts for 25% of bread sales and low fat milks for over 20% of total milk sales.

Dark cutting beef (DCB) is characterised by its high ultimate pH, purple black colour, firm texture and dry surface. This meat has become an economic problem because of its unacceptability to the consumer especially under normal retail conditions. Even with this economic pressure little information is available, in this country, concerning the incidence of high ultimate pH beef or the factors that could effect it. This work examines the occurrence of high ultimate pH meat (>6.0) and the effects of pre-slaughter handling.

It is well established that the proportion of saturated fatty acids in cows milk fat can be reduced by dietary inclusion of fats containing a large proportion of C18 fatty acids. Regardless of the individual C18 acids added to the diet, because unsaturated C18 fatty acids are biohydrogenated in the rumen it is principally the amount of 18:0 absorbed by the animal which is increased. This leads to increased mammary uptake and desaturation of 18:0 and to the secretion in milk of greater amounts of 18:0 and 18:1 fatty acids. Intramammary synthesis of 6:0-16:0 fatty acids is concurrently reduced. Of the cereals grown in the UK, oats contain relatively large amounts of C18 fatty acids. For this reason we have examined the potential of dietary inclusion of oats as a simple and inexpensive means of manipulating milk fat composition. In a previous experiment in which hay-based diets were given replacement of barley with oats reduced the saturated (6:0-18:0) fatty acids in milk fat from 753 to 619 g/kg and increased the monounsaturated fatty acids from 211 to 344 g/kg milk fat.

The extension of the milk quota system to include milk fat as well as milk yield has focussed attention on the control of milk composition by dietary means. For example, when dairy farmers are faced with the need to reduce milk yields to stay within quota they may choose to reduce the herd's intake of concentrates. If they do this they run the risk of increasing the weighted average milk fat concentration of their annual milk supply to a level at which, according to current regulations, they are deemed to have produced a greater volume of milk. Additionally, in the long term an ability to reduce the fat content of milk in a predictable manner in response to the increasing demand for low-fat products might become beneficial. The characteristics of a cow's diet that would enable such predictions to be made with adequate precision need to be identified.

Low-glucosinolate rapeseed meal (<20 μmol/g) is likely to replace the high-glucosinolate meal currently produced in the UK, and in this experiment the use of low-glucosinolate rapeseed meal (RSM) as the sole protein supplement in a compound feed for milk production in cows was assessed. There were three compound concentrate feeds of similar energy and protein content, 0% RSM (group A), 15% RSM (B) and 30% RSM (C). The additional protein in diets A and B was provided as soyabean meal (SBM).

Eighteen Friesian cows were divided into three groups, balanced with regard to previous yield and number of lactations, and three weeks after calving were given one of the compound feeds in a 3x3 changeover experiment; each of the three feeding periods was four weeks. Barley meal was given as a parlour feed, 1 kg air dry at each milking, and the compound concentrate and grass silage were given at Broadbent-Calan gates in quantities related to expected milk yield.

In a previous experiment (Hovell et al. (1987)) it was found that with two roughages, one of good (hay) and the other of poor (straw) degradability, both ground and pelleted, that the voluntary intake of the hay was (60% greater than that of the straw. This was despite the fact that rumen DM pool sizes were very similar. The outflow of undegraded material from the rumen was much greater with the hay although particle size should not have been a constraint to outflow with either roughage (Poppi et al. (1980)), and indeed their particle size distributions were very similar. It was suggested that there might have been an effect of roughage quality on rumen outflow rate, possibly mediated through an effect on reticulo-rumen contractions.

The objective of the experiment reported here was to examine the effect of roughages with different degradabilities on voluntary intake, rumen volume, rumen outflow rate, and on reticulo-ruminal contractions.

This equipment records egg weight (g) shell colour (% reflectance) shell weight (g) and thick albumen height (measured on an egg broken out onto a flat plane), and through the connection with a dedicated microprocessor derives the Haugh units (a logarithmically transformed measure of albumen height) and shell weight per unit surface area (mg/cm2). Means, standard deviations and coefficients of variation for a batch are transferred to a printer and/or microprocessor.

Experiment 1

Three operators each made three sequential measurements of egg weight and shell colour on 31 eggs, each record being automatically captured by the microprocessor.

Experiment 2

Using the same procedure four operators made two sequential measurements of egg weight, shell colour and albumen height on 30 eggs.

Since 1970, farming income in the UK has declined by 36% in real terms (Gretton Report. CLA 1985). Over the same period there has been a marked increase in the production of all the main agricultural commodities in the EC. This has resulted in the supply exceeding demand at existing level of support prices. The cost to the EC commission and to the UK government of supporting this excess production is a serious burden. Over the last forty year3 there has been a huge expansion in countryside recreation in the UK with 84% of people visiting the country at least once a year (NCRS.1984). ‘The reason is not only more individual spare time and money for leisure pursuits but also an upsurge in demand for access to fresh air, fresh views and fresh activities’ (C.C. CCP.224 .1987). At present, the UK government is seeking to reduce the financial support for the production of agricultural commodities and to provide encouragement for alternative uses of land. Section 22 of the Agricultural Act 1986 makes grant aid available for ancillary businesses on or adjacent to farms.

In recent years, interest in the use of chemically treated crop by-products, such as straw, as animal feed has been increasing. So far, most treatment methods which have been developed involve highly technical procedures requiring skilled labour, complex machinery and hence, large amounts of capital. The aim of the work reported here was to assess the feasibility of using a simple dip method to treat straw with both NaOH (to improve digestibility and hence intake) and urea (to increase the nitrogen content) and subsequently to investigate the effects of feeding this straw to young goats. Results were compared with those obtained for commercially-treated and untreated straw.

The dip treatment method involved immersing small bales (density = 69kg/m3 ) in a NaOH (llg/dm3) and urea (7g/dm3) solution for 45 minutes followed by draining for 2 hours and storage for 3-6 days prior to feeding (unchopped).

Rumen bacterial urease is known to be a nickel-dependent enzyme and work in USA has shown that the addition of Ni to ruminant diets can increase the activity of urease in rumen fluid (Spears et al., 1977) and in rumen epithelial tissue (Spears et al., 1979)- In practical feeding trials the addition of 5 ppm Ni has also been shown to increase growth rate and feed conversion efficiency in lambs and steers given high-energy low-protein diets (Spears et al., 1979; Spears, 1984). On the basis of these findings it has been suggested that Ni acts by virtue of its effect on rumen urease activity to enhance the recycling of urea-N to the rumen when dietary N supply is low (Spears, 1980). This hypothesis however does not appear to have been tested by direct measurements of the effect of Ni supplements on urea synthesis and degradation rates in ruminants given low protein diets.

The numerous factors involved in the control of food intake by ruminants have been reviewed in detail (Baile and Forbes, 1974.). Distension of the rumen is thought to limit the voluntary intake of hay by dry cows (Campling and Balch, 1961) and by lactating cows (Mbanya, Anil and Forbes, 1987). In more recent reports, it is thought that some of these factors which are negative feedback signals combine additively in their effects to induce satiety (Forbes, 1986). Prior to investigating the additive effects of rumen distension to those of other feedback signals on intake of silage by lactating dairy cows, we carried out a preliminary study now reported to establish a response curve to different levels of distension which will enable an appropriate degree of distension to be imposed in future experiments involving combinations of treatments.

Animals and Housing - Five rumen fistulated, non-pregnant Friesian cows in early lactation (mean daily milk yield, 25.2 kg) were used in a 5 x 5 Latin square design with a row omitted.

Rice straw was ensiled in laboratory containers of 11 capacity. Three concentrations of moisture (50, 60 or 70%) 3 concentrations of a commercial cellulase enzyme preparation (0, 5 or 10g/kg dry matter (DM)) and 3 types of straw processing (2 cm, 5 mm or 2 mm length) were used. The preparations were stored at room temperature (approximately 20°C) for 30 days. The straw treated with cellulase had a lower final pH (5.21, 4.87, 4.82; P<0.05), higher concentrations of lactic acid (198, 383, 367 mg/100g; P<0.05), a lower content of neutral detergent fibre (689, 630, 620 g/kg DM; P<0.05) and a higher solubility, measured as washing losses from nylon bags (152, 196, 212 g/kg DM; P<0.05) for the 0, 5 and 10 g/kg cellulase treatments respectively. The samples were subsequently incubated in nylon bags in the rumen of 3 sheep for 8, 16, 24, 48 and 72 h to estimate degradation rate and potential degradability using the expression p+a+b(1-e-ct) where p is degradability at time t and a, b and c are constants. While there was no effect of moisture content or physical form of the straw, the degradation rate constant (c) was significantly increased (P<0.05) by the addition of cellulase. The maximum potential (a+b) however was unchanged. The values for c were 0.0496, 0.0677 and 0.0847/h-1 and the values for (a+b) were 624, 621 and 628 g/kg for the 0, 5 and 10 g/kg cellulase enzyme additions respectively. It is concluded that the use of cellulase enzymes can assist in the preservation of wet straw and can result in improved degradation characteristics.

This study was undertaken to obtain information on the digestion and utilization of whole grain faba bean and barley diets by young sheep with a view to providing a better understanding of the factors leading to differences in production that occur when these grains are fed to grazing animals.

Compared with stack treatment the literature contains little information on the nutritive value of cereal straws treated with ammonia in “ovens” at elevated temperature. Recently,Mason et al (1987) and Givens et al (1987) have studied in vitro and in vivo respectively the effect on chemical composition, digestibility and energy value of treating barley, wheat and oat straws with ammonia by the oven method. Substantial changes in chemical composition and nutritive value were found as a result of treatment.

Reid and Ørskov (1987) have suggested that the dry matter (DM) degradation characteristics of straw as measured by the nylon bag technique provide a good prediction of its nutritive value. The aims of the experiment reported here were therefore to examine using the straws of Mason et al (1987), the effect of oven ammonia treatment on the DM degradation characteristics and to assess whether these parameters could be used to predict the metabolisable energy (ME) content of the straws.

Little attention has been directed at defining the ‘protein’ fraction of silages. This component is normally estimated by fractionation based on solubility characteristics and under the conditions most commonly used, nucleic acids (ribonucleic acid (RNA) and deoxyribonucleic acid (DNA)) would appear in the protein fraction. Grasses and legumes can contain appreciable amounts of nucleic acids ranging from 11-29 and 19-53 g/kg dry matter respectively (McAllan, 1982). No information is available as to the effects of ensilage on these nucleic acids. Microbes also contain appreciable amounts of nucleic acids which can account for 150-200 gN/kg total-N of the cell and these amounts may vary according to the stage of growth. It has been suggested (Ullrich, 1982) that microbial-N contribution to the total-N content of silage is as much as 220-280 g/kg. Thus the total amount of silage ‘protein-N’ present in the form of nucleic acid-N (from both plant and microbes) could be appreciable leading to a considerable overestimation of the ‘protein’ content of the silage.

Fats are important energy-yielding raw materials in diets for poultry. It is well known however that they are extremely variable commodities, with factors such as chain length and degree of saturation of constituent fatty acids together with the proportion of free fatty acids having significant effects on fat dietary energy values. A further factor which may affect their utilisation is the age of the bird to which they are fed together with the rate of inclusion. Quantifying this effect would not, however, appear to have been studied in detail. The objective of the current study was an investigation into the interactions between age of bird, fat chemical structure and rate of Inclusion of fat on apparent metabolisable energy (AME) values.

Soya bean (Glycine max) contains large quantities of lectin, which has been implicated as an important anti-nutritional component of animal feeds; but the significance of this has previously been difficult to assess, since no simple method has been available to accurately measure lectin concentration.

We have now developed an assay method suitable for the routine screening of animal feeds using minimal laboratory apparatus. The technique relies upon an enzyme linked immunusorbent assay (ELISA) system, to give a visible colour indication of the presence of SBL.

Samples (100 ul) are serialy diluted on microtitre plates prior coated with affinity purified rabbit anti-SBL antibody. Bound lectins are then detected using a second anti-SBL antibody raised in sheep, followed by an alkaline phosphatase conjugated pig anti (goat) IgG. The addition of p-nitrophenyl phosphate disodium (Sigma 104) substrate gives a yellow colour in the presence of lectin.

The fertility of ewe lambs is usually lower than that of mature ewes. Early embryo loss has been implicated as a cause of reduced fertility, especially when matings occur at the pubertal oestrus (Hare and Bryant, 1985). The Introduction of vasectomised rams to ewe lambs may hasten the occurrence of puberty and, if the introduction of fertile rams is not advanced, mating may occur later in the breeding season with possible advantages to fertility. This experiment investigated the effects of a period of association with vasectomised rams preceding the introduction of entire rams upon (1) the occurrence of puberty, and (2) the fertility of ewe lambs.